A freshly regened hybrid battery will mask a bad cell. You need to load that cell while you're testing it. I use just a 1157 tail light bulb and some test leads. The bad cell or cells will drop quickly.

need to perform a load test to determine which cells are bad. no guessing bro

It may not be the Hybrid Battery it could be something else . You need to check and see If the ABS system lost the 12 volts from the 12 Volt Battery being bad or disconnected or if the brakes are bled it can turn on the ABS light and set a fault a code . Also the Brake Pump may have failed . You need to read the code and figure out if the ABS has lost its Settings or what is wrong by looking up the code . It is a difficult process to reset the Parking Brake setting you'll need to get help from a professional if you can not do it yourself also you'll need a tool cable of resetting the ABS brake pump settings before the Light will go out permanently . You also need to follow and do the process exactly especially to wait the needed time for it to work or it will not work and you will need to try again . I had this issue on a 2012 Prius V with a faulty Hybrid battery . When disconnecting the 12 Volts it lost the Memory to the ABS and I had to reset the Parking brake it is controlled by a Brake Pump Control system and I was after many times of trying finally able to reset it with a THINKSCAN PLUS S7 - OBD2 Scanner ABS/SRS/Engine/Transmission/BCM/AC/IC Reset Code Readers & Scan Tool. It will Help Diagnose the issue .I found it to be well worth the cost . It has many functions available Also the code may set if you bleed the brakes . The Best thing I can say is determine if the car is worth the cost . They aso have Engine issues if the oil is filled to the top . And You know when you hear a rattle other websites address this issue . Good Luck Hope it helps someone stuck .

Were you able to find out what was wrong with the HV, please share

Dr Prius has an App that can Help with the Hybrid battery and test it without going into the Hybrid Battery Or Cells . Make sure you have a good 12 volt battery also

i have no corrosion, clean enough fans, and voltache close to each other,, but CHK Battery shows up

Yo Im in the same boat. How has it been after you did this?